We selected a FISH probe targeting the CDKN1B locus (Cyclin-Dependent Kinase Inhibitor 1B, 12p13.1) because CDKN1B is located in the center of the commonly deleted 12p region [6], and it encodes p27/kip1, a well known tumor suppressor gene with importance in various cancer types (reviewed in [27, 28]. Here, CDKN1B is linked to cancer.